MediumCalculus & Linear Algebra

Eigenvalues of a 2×2

Goldman SachsCitadel

What is the larger eigenvalue of the matrix (2112)\begin{pmatrix} 2 & 1 \\ 1 & 2 \end{pmatrix}?

Approach

Solve det(AλI)=0\det(A - \lambda I) = 0.

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